It is well known to those skilled in the art that aromatic hydrocarbons are a class of very important industrial chemicals which find a variety of uses in petrochemical industry. Recent efforts to convert gasoline to more valuable petrochemical products have therefore focused on the aromatization of gasoline to aromatic hydrocarbons by catalytic cracking in the presence of a catalyst. The aromatic hydrocarbons produced by the aromatization process include C.sub.6 to C.sub.8 hydrocarbons such as benzene, toluene and xylenes (hereinafter collectively referred to as BTX) which can be useful feedstocks for producing various organic compounds and polymers. However, heavier, less useful aromatic compounds are also produced during the aromatization process. It is, therefore, highly desirable to convert these compounds to the more useful BTX.
Though a number of catalysts have been used in a hydrodealkylation or transalkylation process, the conversion of a C.sub.9 + aromatic compound and the selectivity to BTX are generally not as high as one skilled in the art would desire. Furthermore, a catalyst used in the hydrodealkylation or transalkylation of these heavier aromatic compounds is generally deactivated in a rather short period because of depositions of carbonaceous material such as, for example, coke on the surface of the catalyst.
Furthermore, ethylbenzene is produced during a gasoline aromatization process. Ethylbenzene is undesirable because it is difficult to separate from xylenes which are a more valuable product than ethylbenzene.
Accordingly, there is an ever-increasing need to develop a catalyst and a process for converting these heavier and less useful aromatic compounds (mainly trimethyl- and tetramethylbenzenes) to the more valuable BTX hydrocarbons while simultaneously suppressing the coke formation and reducing the ethylbenzene content. Such development would also be a significant contribution to the art and to the economy.